How do I delete a shader node (From Script)?
You can do something like this:

import bpy

#Get the material you want (replace the name below)
mat = bpy.data.materials['Material']

#Get the node in its node tree (replace the name below)
node_to_delete =  mat.node_tree.nodes['Principled BSDF']

#Remove it
mat.node_tree.nodes.remove( node_to_delete )